Air conditioning systems for the setting of a desired room climate are known in principle and have a condenser, an evaporator, an expansion device (either an orifice or a thermal expansion valve) and a compressor. Compressors with variable displacement are often used with an evaporator off air temperature or an evaporator fin temperature sensor in air conditioning systems, in particular automotive air conditioning systems. The driving of the compressor of an air conditioning system of this kind is usually done by the drive aggregate of the vehicle, with the force transmission usually taking place via a belt or the like. The coupling in of the drive takes place in this through a clutch which is electrically controllable. Through engaging and disengaging of the clutch, however, torque fluctuations can be transmitted to the drive train of the vehicle, which is noticeable by the vehicle passengers as a jolt.
Furthermore the wear of the clutch plates is increased through an uncontrolled engaging and disengaging of the clutch.